A small US presence in an eastern town called Deir Ezzor has maintained an iron grip on the oil fields and even repelled an advance of hundreds of pro-Syrian government forces— including some Russian nationals believed to be mercenaries — in a massive battle that became a lopsided win for the US.
Russia has advanced weapons systems in Syria, pro-Syrian government militias have capable Russian equipment, and Iran has about 70,000 troops in the country. On paper, these forces could defeat or oust the US and the Syrian rebels it backs, but in reality it would likely be a losing battle, according to an expert.
“They have the ability to hurt US soldiers — it’s possible,” Tony Badran, a Syria expert at the Foundation for Defense of Democracies, told Business Insider. But “if they do that,” he said, “they’ll absolutely be destroyed.”
In Badran’s view, even if Russia wanted a direct fight against the US military in Syria, something he and other experts seriously doubt, the forces aligned with Syria’s government don’t stand much of a chance.
“I think the cruise-missile attack in April showed, and the ongoing Israeli incursions show, the Russian position and their systems are quite vulnerable,” said Badran, referring to the US’s April 2017 strike on a Syrian airfield in response to a chemical-weapons attack in the country. Though Russia has stationed high-end air defenses in Syria to protect its assets, that did not stop the US when President Donald Trump’s administration decided to punish the Syrian air force with 59 cruise missiles.
Russia has just a few dozen jets in Syria, mostly suited for ground-attack roles with some air-supremacy fighters. The US has several large bases in the area from which it can launch a variety of strike and fighter aircraft, including the world’s greatest fighter jet, the F-22.

In Iraq, an insurgency used terrorist tactics — including car bombs and IEDs — against the occupying U.S.-led coalition forces. In Syria, U.S. forces are on the side of the insurgents (rebels fighting Assad’s regime) and the local Syrians, who have survived the brutality of ISIS, want no part of any kind of Islamic extremism. While the situation could conceivably change, a rather small force of U.S. troops is currently able to control a key region in Syria simply because anyone who attacked them would suffer a devastating counter-attack backed by everything the U.S. military can bring to bear, up to and including bombing raids by B-52s.

The Pentagon Monday leveled sharp criticism at a military offensive on northern Syria, which has displaced tens of thousands of Kurds, killed hundreds of civilians and is creating a humanitarian crisis, all while carefully not mentioning the country carrying out the offensive, Turkey.
“Civilian casualties, not getting humanitarian assistance, a growing humanitarian crisis. It’s gotta be stopped. It’s gotta be averted,” Col. Rob Manning, a Pentagon spokesman, told reporters.
Pressed by a reporter from the Turkish Anadolu News Service about who specifically was to blame for the worsening situation in the North, Manning refused to name Turkey, a NATO ally, and simply called on all sides to stop. . . .
The US has complained to Turkey that its two-months-old offensive, which captured the city of Afrin over the weekend, is siphoning off Kurdish fighters from the fight against ISIS in the east to battle Turkish and Syrian rebel troops in the west.

On the one hand, we would like to remain on friendly terms with Turkey. On the other hand, there are limits to such friendship.